Uranium-238 has a half-life of an incredible 4.5 billion years. Uranium-235 has a half-life of just over 700 million years.
What are the half lives for uranium 235 and uranium-238?
The half-life of uranium-238 is about 4.5 billion years, uranium-235 about 700 million years, and uranium-234 about 25 thousand years.
What is the half-life of uranium-238?
Uranium-238 decays by alpha emission with a half-life of (4.4683 ± 0.0048) × 109 years (Jaffey et al., 1971) to 234Th, which in turn decays (half-life = 24.1 days) by beta emission to 234Pa, which decays (half-life = 6.7 h) by beta emission to 234U, which decays (half-life = 245 620 ± 250 years; Cheng et al., 2012) by
What is the half-life of uranium-238 and lead 206?
4.5 billion years For example, uranium-238 (which decays in a series of steps into lead-206) can be used for establishing the age of rocks (and the approximate age of the oldest rocks on earth). Since U-238 has a half-life of 4.5 billion years, it takes that amount of time for half of the original U-238 to decay into Pb-206.